Sift the whole wheat flour with baking powder, baking soda and cinnamon powder and keep aside, powder the rolled oats in a mixture grinder and keep it aside.
In a bowl take butter, add brown and white sugar to it and beat it nicely for 8-10minutes till slightly fluffy, then add yogurt and again mix well.
Then add the mashed bananas and mix nicely with a hand beater for 2-3minutes
Then add the sifted wheat flour, and powdered oats and slowly mix it nicely by adding milk.
Then add vanilla essence and walnuts and mix everything nicely.
Pour the batter in a baking tin lined with parchment paper, sprinkle some walnuts and oats over the batter and bake it in a preheated oven for 45 minutes on lower rack, both coil on.
Check by inserting a toothpick, if it comes out clean after 45minutes then remove the cake from the oven and cool it on a wire rack for 2 hours before slicing it, incase if the toothpick does not come out clean keep for 8-10minutes more by turning on only the lower rack of the oven.
